Backstage Functions

Backstage Functions is an Open Source Serverless Platform able to store and execute code.

Benefits

• Your code will be executed in an isolated environment
• You don't have to worry about infrastructure
• Functions can be called at any time by any project

FAQ

• Which languages are supported? Currently, only Javascript.

• Is it based on events? Not yet.

• How the code execution happens in an isolated way? It uses the Backstage Functions Sandbox.

Running locally without Docker

Requirements

• Redis 3.0+
• NodeJS 8.13.0

Download the project

git clone https://github.com/backstage/functions.git

Setup

make setup

Run

make run

Configuration

To format your log in json, please run:

export LOG_APP_FORMAT=json

Running locally via Docker

Requirements

• Docker 1.12+
• Docker compose 1.8+

Download docker-compose.yml

mkdir functions
cd functions
curl 'https://raw.githubusercontent.com/backstage/functions/master/docker-compose.yml' > docker-compose.yml

Run

docker-compose up

How to use

Function Structure

Your function will have a file, which you define any name you want, and it has to have a function called main, with two parameters: req and res. Req represents the Request and Res represents the Response. At the end of your code, you'll have to use the send method.

Example of a function

function main(req, res) {
  const name = (req.body && req.body.name) || "World"
  res.send({ say: `Hello ${name}!` })
}

Setting a function

To set your function, you can make a PUT request to /functions/:namespace/:name:

curl -i -X PUT http://localhost:8100/functions/example/hello-world \
    -H 'content-type: application/json' \
    -d '{"code":"function main(req, res) {\n  const name = (req.body && req.body.name) || \"World\"\n  res.send({ say: `Hello ${name}! Nice meeting you...` })\n}\n"}'

Ps: if it doesn't exists, it will be created

Deleting a function

To delete your function, you can make a DELETE request to /functions/:namespace/:name:

curl -i -X DELETE http://localhost:8100/functions/example/hello-world \
    -H 'content-type: application/json'

Executing a function

To execute a function, you can make a PUT request to /functions/:namespace/:name/run:

curl -i -X PUT http://localhost:8100/functions/example/hello-world/run \
    -H 'content-type: application/json'

The result will be something like:

HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Content-Length: 22
ETag: W/"16-soBGetwJPBLt8CqWpBQu+A"
Date: Tue, 11 Oct 2016 16:51:04 GMT
Connection: keep-alive

{"say":"Hello World!"}

If one needs to pass an object in the request, the payload is executed:

curl -i -X PUT http://localhost:8100/functions/example/hello-world/run \
    -H 'content-type: application/json' \
    -d '{"name": "Pedro"}'

The result will be something like:

HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Content-Length: 22
ETag: W/"16-Ino2/umXaZ3xVEhoqyS8aA"
Date: Tue, 11 Oct 2016 17:13:11 GMT
Connection: keep-alive

{"say":"Hello Pedro!"}

Executing functions in a pipeline

To execute many functions in a pipeline, you can make a PUT request to /functions/pipeline:

// Function0
function main(req, res) {\
  res.send({x: req.body.x * 10});

}

// Function1
function main(req, res) {
  res.send({x: req.body.x * 20});
}

$ curl -g -i -X PUT 'http://localhost:8100/functions/pipeline' \      
    -H 'content-type: application/json' \
    -d '{"steps": [{"namespace":"namespace", "id":"function0"}, {"namespace":"namespace", "id": "function1"}], "payload":{"x":1}}'

Considering the curl above, the pipeline result would be like this:

HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Content-Length: 22
ETag: W/"16-Ino2/umXaZ3xVEhoqyS8aA"
Date: Tue, 11 Oct 2016 17:13:11 GMT
Connection: keep-alive

{"x": 200}